I think it is y=-.25
7*3 - 4y = 20
21 - 4y = 20
subtract 21 from each side
- 4y = - 1
divide each side by - 4
y= -.25
I believe thugs is it
4.718592e+15
G(-4)
=1/2((-4)-1)
=1/2(-5)
=-2.5
------------------------------
f(g(-4))
=f(-2.5)
=2(-2.5)+1
=-5+1
=-4
You can only add exponents if you are multiplying two of the same variable together. For example,

You take them away if you are dividing.
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In a polynomial equation, you can add together two of the same variable if they have the same exponent
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Or you can take them away in a similar fashion,
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But you cannot add two (or more) different exponents,
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(it does not get any simpler)
I hope this has answered your question, if not, leave a comment and I'll update the answer.
Answer:
Step-by-step explanation:
Both 115 and 145 mph are above the mean. Draw a normal curve and mark these speeds. 115 mph is 1 standard deviation above the mean; 130 would be 2 standard deviations above the mean; and 145 would be 3 s. d. above it.
We need to find the area under the standard normal curve between 115 and 145. This is equivalent to the area under the standard normal curve between z = 1 and z = 3.
I used my TI-83 Plus calculator's DISTR function "normalcdf(" to calculate this area: normalcdf(1, 3) = 0.1573.
The area between z = 1 and z = 3 is 0.1573. In other words, the percentage of serves that were between 115 and 145 mph was 15.73%.